Improvement in extension tables



2 Sheets--Sheet1.-

M. C0 LE MAN.

Extension Tables.

kw/mf. M,

UNITED STATES MATTHEW-COLEMAN, or 10mm, MICHIGAN.

IMPROVEMENT IN EXTENSION TABLES.

Specification forming part of Letters Patent No. 136,705, dated March 11, 1873.

To all whom it may concern:

Be it known that I, MATTHEW COLEMAN, of Ionia, in the county of Ionia and in the State of Michigan, have invented a new and useful Improvement in Slides for Extension tion of their bearing-faces; and Fig. 4 is a cross-section on line :0 m of Fig. 2.

, Letters of like name and kind refer to like parts in each of the figures.

The design of my invention is to increase the efliciency and durability of the slides of extension tables, and to render them more easy of operation by decreasing the lateral friction between their bearing-surfaces; to which end said invention consists in the peculiar construction of the slides and the means employed for lessening their lateral friction and for combining them together, substantially as and for the purpose hereinafter specified.

In the annexed drawing, A and A represent a series of slides, provided within one face with three grooves, a, and upon the op-- posite face with three tongues, a, which latter correspond in size and relative position to the like features of said grooves, and fit into the same when said slides are combined. From one end to a point near the opposite end the center tongue of each slide is removed, and a groove, a, formed in its place, while within the opposite end of the corresponding center groove a of the contiguous slide is placed a tongue, a, which fits into said groove a. Within the coincident grooves a and a, between the short tongues a and a, is placed a roller, B, which has a diameter slightly greater than their combined depth and a thickness slightly less than their width,

which'roller, when said slides'are pressed together and moved longitudinally in opposite directions, operates as a rolling bearing, and prevents the friction that would otherwise be caused by the contact of the bearing-surfaces. When moved outward until their ends engage with opposite sides of the roller, the short central tongues operate as stops to prevent the further outward movement of said parts. The slides thus constructed are arranged in two sets, and the outer ones secured to or upon one section, G,.of*a table, while the inner ones are attached to the opposite section 0. The outer or free ends ofieach correspondingpair of slides are now connected together by means of a bar,D, which extends between and is secured to each, as seen in Figs. 1 and 2, by which arrangement the relative lateral positions of said slides areinsured. When drawn outward to their furthestdimit the short central tongues operate as stops,'as before stated, while the inward motion of said slides is limited by the cross-bars, which impinge upon each other, as seen in Fig.2.

The slides thus constructed possess in an unusual degree rigidity and durability, while all stoppages from lateral friction, caused by the moving of one side of a section in advance of the opposite side, is effectually prevented by the rollers. V j

Having thus fully set forth the nature and merits of my invention, what I claim as new is The slides A and A, provided with the grooves a and a and with the tongues a and a, containing within their central grooves the horizontally-revolving rollers B, and combined by means of the cross-bars D, substantially as and for the purpose specified.

In testimony that I- claim the foregoing I have hereunto set my hand this 27th day of January, 187 3.

MATTHEW COLEMAN.

Witnesses:

A. W. DODGE, WM. B. THOMAS. 

